this paper considers the problem of stable limit cycles generating in a class of uncertain nonlinear systems which leads to stable oscillations in the system’s output.this is a wanted behavior in many practical engineering problems. for this purpose, first the equation of the desirable limit cycle is achieved according to shape, amplitude and frequency of the required output oscillations. then,...

congenital left ventricular diverticulum is a rare cardiac malformation. two categories of congenital ventricular diverticulum have been identified with regard to their localization: apical and non-apical. apical diverticula are always associated with midline thoraco-abdominal defects and other heart malformations. non-apical diverticula are always isolated defects. diagnosis is established by ...

the importance of the role played by bacteria in the pathogenesis of pulpal and apical disease has been established. one of the characteristics of apical periodontitis is apical bone resorption, which is due to apical immune response to bacterial infection. recently, novel bacterial complex lipid called phosphorylated dihydroceramides has been discovered to be of inflammatory activators. the ba...

a label-free electrochemical nucleic acid aptasensor for the detection of methamphetamine (ma) by the immobilization of thiolated self-assembled dna sequences on a gold nanoparticles-chitosan modified electrode is constructed. when ma was complexed specifically to the aptamer, the configuration of the nucleic acid aptamer switched to a locked structure and the interface of the biosensor changed...

introduction: preserving the apical root structure during cleaning and shaping of the canal has always been a challenge in endodontics particularly when the root canals are curved. the purpose of this in vitro study was to compare the apical transportation induced by the reciproc and biorace rotary systems in preparing the mesiobuccal root canal of the human maxillary molars. materials and meth...

a 20-year-old man presented with the history of pain and swelling in the anterior maxillary segment. the periapical radiography was indicative of a dental anomaly in right maxillary lateral incisor. due to the insufficient information from conventional radiography, cone-beam computed tomography (cbct) was ordered. cbct showed apical root resorption, large apical lucency and two separate canals ...